Articulate pipe-coupling joints have been known before. A typical such arrangement has been seen in patents at least as early as 1885, as seen in Patton, U.S. Pat. No. 318,790. A later patent representative of a more recent innovation in the design of pneumatic, fluid-conducting articulate swivel joints may be seen in Hulsey, U.S. Pat. No. 3,409,270. As may be appreciated by any cursory search through patented or technological teachings of pipe-coupling and pneumatic conveying articulate joints, fluid from one pipe or conduit enters into the joint areas, wherein a chamber is usually provided. The chamber usually opens pneumatically to a chamber of the second pipe or conduit. The pipes are articulate or movable about some pivot point or pivot line which usually extends through the chamber in some fashion.
In the past, it has been found that fluids passing from one conduit to the other conduit through such articulate joints, are faced with a flow restriction and turbulence when the fluid enters into the expanded chamber of one conduit which complementally faces a similar expanded chamber of the second conduit. In some cases fluid from one conduit must enter into a narrower passageway, thus being subject to a baffle or restriction means in its flow. In all articulate swivel conduit couplings known before, the fluid is affected in its flow in such detrimental manners. It has been sought in certain, specific fluid conduit coupling arrangements to have an articulate, movable swivel assembly through which fluid may flow without baffle or constrictive influences by sudden and abrupt changes in the flow chamber of one conduit complementally opening into the flow chamber of the second conduit.